ORIGINAL COMMUNICATIONS. 



On the Structure and Mode of Formation of Starch 

 Granules, according to the Principle of "Molecular 

 Coalescence." By George Rainey, M.R.C.S., Lecturer 

 on Microscopical Anatomy at St. Thomas's Hospital. 



Starch, from its physiological importance, remarkable 

 structural peculiarities, and general diffusion through the 

 vegetable kingdom, has been a favourite subject of investiga- 

 tion with physiologists and microscopists. However, not- 

 withstanding the attention which has been devoted to its 

 structure and development, it is acknowledged by the greatest 

 physiologists to be known but little of. (See Mr. Busk's 

 paper on " Starch Granules," in the number of the ' Quar- 

 terly Journal of Microscopical Science' for April, 1853.) 

 There are, doubtless, intrinsic difficulties attending the inves- 

 tigation of this substance, but these have been very much 

 augmented by the principle on which the examination has 

 been conducted, namely, the cellular hypothesis. If this 

 hypothesis had been in itself correct, and admissible as a 

 basis of explanation of the facts connected with the structure 

 and mode of formation of the starch granule, it ought, con- 

 sidering the amount of talent and ingenuity which have been 

 employed in its application to these inquiries, to have thrown 

 more light upon these much disputed, and as yet entirely 

 unsettled questions. 



After this apology for thus differing from the high and 

 almost universally credited authorities of the present day, I 

 shall proceed to explain on a new principle — one strictly me- 

 chanical in its immediate operation — " the principle of mole- 

 cular coalescence," — those points connected with the structure 

 and development of starch granules, by which physiologists 

 and botanists have been so long puzzled. In this paper the 

 same train of reasoning will be employed, and the same 

 experimental data adduced, as in my last paper, that on the 

 " Structure and Mode of Formation of the Dental Tissues," 

 as also in that on " Shell Structures ;" and hence, though 

 treating of a very different class of organized structures, thi* 

 is still but an extension of my former researches. 



VOL. VIII. B 



